Light emitting device package

ABSTRACT

A light emitting device package including a substrate; a light emitting device on the substrate; a first heatsink between the substrate and the light emitting device to transfer heat generated from the light emitting device; a second heatsink disposed below the first heatsink; and an electrode between the first heat sink and the light emitting device. Further, the substrate is disposed between the first and second heatsinks and is narrower at a position between the first and second heatsinks than at a position not between the first and second heatsinks, a material of the substrate is the same at the position between the first and second heatsinks as not between the first and second heatsinks, and the substrate at the position not between the first and second heatsinks surrounds the first and second heat sinks.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of prior pending application Ser. No.13/719,666, filed on Dec. 19, 2012, and a Continuation of prior pendingapplication Ser. No. 12/709,973, filed on Feb. 22, 2010, which claimspriority under 35 U.S.C. §119(e) to Korean Patent Application No.10-2009-0014789, filed on Feb. 23, 2009. The entire contents of theabove applications is hereby incorporated by reference in its entirety.

BACKGROUND

Embodiments relate to a light emitting device package and a method ofmanufacturing the same.

A light emitting diode (LED) has been widely used as a light emittingdevice.

The LED includes a first conductive type semiconductor layer, an activelayer, and a second conductive type semiconductor layer, which aresequentially stacked on each other so that light generated from theactive layer is emitted to the outside according to a voltage appliedthereto.

A light emitting device package may have a structure in which a lightemitting device is disposed on a silicon (Si) substrate. Since the Sisubstrate has a high thermal resistance, a thermal emissioncharacteristic may be inferior, and also, a light emissioncharacteristic of the light emitting device may be degraded.

SUMMARY

Embodiments provide a light emitting device package having a novelstructure and a method of manufacturing the same.

Embodiments also provide a light emitting device package having animproved thermal emission characteristic and a method of manufacturingthe same.

In one embodiment, a light emitting device package comprises: asubstrate; a light emitting device on the substrate; a first heatsinkbetween the substrate and the light emitting device, the first heatsinkbeing at least partially disposed within the substrate to transfer heatgenerated from the light emitting device; first and second electrodeselectrically separated from each other, the first and second electrodesbeing electrically connected to the light emitting device.

In another embodiment, a light emitting device package comprises: asubstrate comprising a cavity; a light emitting device within thecavity; a first heatsink between the light emitting device and thesubstrate; and first and second electrodes electrically separated fromeach other, the first and second electrodes being electrically connectedto the light emitting device.

In further another embodiment, a light emitting device packagecomprises: a substrate; a light emitting device on the substrate; aheatsink disposed below the light emitting device with the substratetherebetween, the heatsink being at least partially buried in a lowerportion of the substrate; and first and second electrodes electricallyseparated from each other, the first and second electrodes beingelectrically connected to the light emitting device.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 5 are views of a light emitting device and a method ofmanufacturing the light emitting device according to an embodiment.

FIG. 6 is a perspective view of a light emitting device according to anembodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description, it will be understood that when a layer(or film) is referred to as being ‘on’ another layer or substrate, itcan be directly on the another layer or substrate, or intervening layersmay also be present. Further, it will be understood that when a layer isreferred to as being ‘under’ another layer, it can be directly under theanother layer, and one or more intervening layers may also be present.Reference will now be made in detail to the embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings. In the following description, words “above,” “one,” “below,”and “underneath” are based on the accompanying drawings.

In the drawings, the thickness or size of each layer is exaggerated,omitted, or schematically illustrated for convenience in description andclarity. Also, the size of each element does not entirely reflect anactual size.

Hereinafter, a light emitting device package and a method ofmanufacturing the same according to an embodiment will be described indetail with reference to accompanying drawings.

FIGS. 1 to 5 are views of a light emitting device and a method ofmanufacturing the light emitting device according to an embodiment, andFIG. 6 is a perspective view of a light emitting device according to anembodiment.

Referring to FIGS. 5 and 6, a light emitting device package includes asubstrate 10, an insulating layer 20 disposed on the substrate 10, afirst heatsink 31 disposed on an upper portion of the substrate 10, asecond heatsink 32 disposed on a lower portion of the substrate 10,first and second electrodes 41 and 42 disposed on the substrate 10 andelectrically separated from each other, and a light emitting device 50electrically connected to the first and second electrodes 41 and 42.

The substrate 10 may be formed of a conductive material or an insulatingmaterial. The insulating layer 20 electrically insulates the substrate10. For example, the substrate 10 may be formed of Si material that isthe insulating material. The insulating layer 20 may be disposed on asurface of the substrate 10 to prevent current from leaking. Theinsulating layer 20 may include a Si oxide layer in which a substrateformed of the Si material is oxidized.

A first cavity (see reference numeral 11 of FIG. 1) is defined in a topsurface of the substrate 10. A second cavity (see reference numeral 12of FIG. 1) is defined within the first cavity 11. The first heatsink 31is buried within at least a portion of the second cavity 12.

A third cavity (see reference numeral 13 of FIG. 1) is defined in abottom surface of the substrate 10. The second heatsink 32 is buriedwithin at least a portion of the third cavity 13. For example, a topsurface of the first heatsink 31 may flush with a top surface of theinsulating layer 20 disposed on a bottom surface of the first cavity 11.A bottom surface of the second heatsink 32 may flush with a bottomsurface of the insulating layer 20 disposed on a bottom surface of thesubstrate 10.

For example, the first and second heatsinks 31 and 32 may be formed ofcopper (Cu) or aluminium (Al) having a superior thermal conductivity,but is not limited thereto.

The first and second heatsinks 31 and 32 are disposed at positionscorresponding to each other. That is, the first and second heatsinks 31and 32 vertically overlap each other. Thus, heat may be effectivelytransferred from the first heatsink 31 to the second heatsink 32. Also,only one of the first and second heatsinks 31 and 32 may be provided.

The substrate 10 may have a thickness of 400 μm to 800 μm. The substrate10 disposed below the first heatsink 31 may have a thickness of 10 μm to20 μm. That is, when all of the first and second heatsinks 31 and 32 isprovided, the substrate 10 between the first heatsink 31 and the secondheatsink 32 may have a thickness of 10 μm to 20 μm. For example, thesubstrate 10 disposed below the first heatsink 31 may have a thicknesscorresponding to 1.25% to 5% of a maximum thickness of the substrate 10.

The substrate 10 between the first heatsink 31 and the second heatsink32 may not be completely removed, but partially remain. Thus, when thefirst and second heatsinks 31 and 32 are buried into the first andsecond cavities 12 and 13, it may prevent a void from occurring.

The first and second electrodes 41 and 42 may extend from the bottomsurface of the substrate 10 to the top surface of the substrate 10 alonglateral surfaces of the substrate 10. Also, the first and secondelectrodes 41 and 42 may pass through the substrate to extend from thebottom surface of the substrate 10 to the top surface of the substrate10.

The first and second electrodes 41 and 42 may be disposed on theinsulating layer 20. The first electrode 41 may extend up to the firstheatsink 31.

In this embodiment, the first electrode 41 may vertically overlap thefirst and second heatsinks 31 and 32 or cover surfaces of the first andsecond heatsinks 31 and 32. For example, the first and second heatsinks31 and 32 may be surrounded by the first electrode 41 and the insulatinglayer 20.

Thus, heat generated from the light emitting device 50 is transferred tothe first heatsink 31 through the first electrode 41, and the heattransferred to the first heatsink 31 is transferred to the secondheatsink 32 adjacent to the substrate 10 and the first heatsink 31. Theheat transferred to the second heatsink 32 is effectively emitted to theoutside through the first electrode 41.

The light emitting device 50 may be a light emitting diode (LED). TheLED may have various structures such as a horizontal type and a verticaltype.

The light emitting device 50 is electrically connected to the firstelectrode 41 and/or the second electrode 42 through a wire 51. In thisembodiment, the light emitting device 50 has one side directlycontacting the first electrode 41 and electrically connected to thefirst electrode 41. Also, the light emitting device 50 is electricallyconnected the second electrode 42 through the wire 51.

Also, the light emitting device 50 may be connected to the firstelectrode 41 and/or the second electrode 42 through a conductive viapassing through the substrate 10. Alternatively, the light emittingdevice 50 may be connected to the first electrode 41 and/or the secondelectrode 42 using a flip chip manner.

The light emitting device 50 may be disposed on the first heatsink 31.Also, the light emitting device 50 may vertically overlap the firstheatsink 31 to effectively transfer the heat emitted from the lightemitting device 50 to the first heatsink 31.

A molding member 14 containing a phosphor may be disposed in the firstcavity 11. Also, the molding member 14 may not contain the phosphor.

A method of manufacturing the light emitting device package according toan embodiment will be described in detail with reference to FIGS. 1 to5.

Referring to FIG. 1, a substrate 10 is prepared. A top surface and abottom surface of the substrate 10 are etched to first, second, andthird cavities 11, 12, and 13.

A mask pattern may be formed on the substrate 10, and then, thesubstrate 10 may be selectively etched using the mask pattern as an etchmask to form the first, second, and third cavities 11, 12, and 13. Forexample, the mask pattern may be formed of silicon nitride.

The second cavity 12 and the third cavity 13 are used for forming afirst heatsink 31 and a second heatsink 32. Here, only one of the secondcavity 12 and the third cavity 13 may be formed.

Referring to FIG. 2, an insulating layer 20 is formed on a surface ofthe substrate 10. The insulating layer 20 may include a Si oxide layerin which the substrate 10 formed of a Si material is oxidized.

Referring to FIG. 3, the first heatsink 31 and the second heatsink 32are formed in the second cavity 12 and the third cavity 13,respectively.

Seed layers may be formed in the second and third cavities 12 and 13,and then, a plating process may be performed on the seed layers to formthe first and second heatsinks 31 and 32.

Alternatively, a metal may be deposited on the second and third cavities12 and 13 to form the first and second heatsinks 31 and 32.

Since the substrate 10 is disposed between the second cavity 12 and thethird cavity 13, the seed layers may be easily formed. Also, the firstand second heatsinks 31 and 32 may be formed on the seed layers toreduce voids within the second and third cavities 12 and 13.

Referring to FIG. 4, a first electrode 41 and a second electrode 42,which are electrically separated from each other are formed on thesubstrate 10.

Since the first and second electrodes 41 and 42 extend from a bottomsurface to a top surface of the substrate, the light emitting devicepackage may be easily installed using a surface-mount technology.

The first and second electrodes 41 and 42 are formed on a bottom surfaceand lateral surfaces of the first cavity 11. Thus, the first electrode41 may cover a top surface of the first heatsink 31. The first andsecond electrodes 41 and 42 may serve as a power supply function as wellas a function that reflects light emitted from the light emitting device50 to improve light efficiency.

Also, the first electrode 41 may contact the first heatsink 31 toeffectively transfer the heat generated from the light emitting device50 to the first heatsink 31.

Referring to FIG. 5, the light emitting device 50 is disposed on thefirst electrode 41. The light emitting device 50 and the secondelectrode 42 are electrically connected to each other using a wire 51.

Since the light emitting device 50 is formed on the first electrode 41,the heat generated from the light emitting device 50 may be effectivelytransferred to the first electrode 41 and the first heatsink 31.

As described above, in the light emitting device package and the methodof manufacturing the same according to an embodiment, at least one ofthe second cavity 12 and the third cavity 13 is formed on the substrate10 to form at least one of the first heatsink 31 and the second heatsink32, which are formed of a metal material. Thus, the heat emitted fromthe light emitting device 50 may be quickly emitted to the outside usingthe first and second heatsinks 31 and 32.

Also, the first and second heatsinks 31 and 32 are vertically disposedwith respect to the substrate 10 and vertically overlap each other.Thus, the heat may be effectively transferred between the first heatsink31 and the second heatsink 32.

The method of manufacturing the light emitting device according to anembodiment may include etching a substrate 10 to form a cavity; forminga heatsink formed of a metal material within the cavity; forming firstand second electrodes 41 and 42, which are electrically separated fromeach other on the substrate 10; and installing a light emitting device50 on the substrate 10 to electrically connect the light emitting device50 to the first and second electrodes 41 and 42.

The etching of the substrate 10 to form the cavity may include formingat least one of a second cavity 12 in a top surface of the substrate 10and a third cavity 13 in a bottom surface of the substrate 10.

The etching of the substrate 10 to form the cavity may include forming afirst cavity 11 in the top surface of the substrate 10 and forming thesecond cavity 12 within the first cavity 11.

The heatsink may include at least one of a first heatsink 31 buried inthe second cavity 12 and a second heatsink 32 buried in the third cavity13. The first heatsink 31 and the second heatsink 32 may verticallyoverlap each other.

Another embodiment provides a lighting system which comprises the lightemitting device package described above. The lighting system may includelamp, street light, back light unit, not limited thereto.

Embodiments can provide the light emitting device package having a novelstructure and the method of manufacturing the same.

Embodiments also can provide the light emitting device package having animproved thermal emission characteristic and the method of manufacturingthe same.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

What is claimed is:
 1. A light emitting device package comprising: asubstrate; a first metal on a top surface of the substrate; a secondmetal under a bottom surface of the substrate; and a light emittingdevice on the first metal, wherein the substrate comprises a firstportion between the first metal and the second metal and a secondportion surrounding the first portion and extending from the firstportion, wherein the first portion has a narrower thickness than athickness of the second portion and the first portion between the firstmetal and the second metal has no hole, wherein an entire bottom surfaceof the first metal contacts the first portion, and wherein a thicknessof the second metal is greater than a thickness of the first portion. 2.The light emitting device package according to claim 1, wherein thefirst metal comprises aluminum.
 3. The light emitting device packageaccording to claim 1, wherein the second metal comprises copper.
 4. Thelight emitting device package according to claim 1, wherein thesubstrate comprises an insulating member.
 5. The light emitting devicepackage according to claim 1, further comprising: a phosphor layeraround the light emitting device.
 6. The light emitting device packageaccording to claim 1, wherein the first metal comprises a first heatsink.
 7. The light emitting device package according to claim 1, whereinthe second metal comprises a second heat sink.
 8. The light emittingdevice package according to claim 1, wherein the first metal isvertically overlapped with the second metal.
 9. A light emitting devicepackage comprising: a substrate comprising a first portion between afirst metal and a second metal and a second portion having thicknessesdifferent from each other, the first portion having a narrower thicknessthan a thickness of the second portion, the first portion between afirst metal and a second metal has no hole; the first metal on a topsurface of the first portion of the substrate; the second metal under abottom surface of the first portion of the substrate; and a lightemitting device on the first metal, wherein an entire bottom surface ofthe first metal contacts the first portion, and wherein a thickness ofthe second metal is greater than a thickness of the first portion. 10.The light emitting device package according to claim 9, wherein thesecond metal comprises aluminum.
 11. The light emitting device packageaccording to claim 9, wherein the second metal comprises copper.
 12. Thelight emitting device package according to claim 9, further comprising:a phosphor layer around the light emitting device.
 13. The lightemitting device package according to claim 9, wherein the first metalcomprises a first heat sink and the second metal comprises a second heatsink.
 14. The light emitting device package according to claim 9,wherein a distance between the first metal and the second metal is in arange from 10 μm to 20 μm.
 15. A light emitting device packagecomprising: a substrate; an electrode on a top surface of the substrate;a metal member under a bottom surface of the substrate; and a lightemitting device on the electrode, wherein the substrate comprises afirst portion between the electrode and the metal member and a secondportion surrounding the first portion and extending from the firstportion, wherein the first portion has a narrower thickness than athickness of the second portion and the first portion between theelectrode and the metal member has no hole, wherein an entire bottomsurface of the electrode contacts the first portion, and wherein athickness of the metal member is greater than a thickness of the firstportion.
 16. The light emitting device package according to claim 15,wherein the metal member comprises copper.
 17. The light emitting devicepackage according to claim 15, wherein the electrode comprises a firstheat sink.
 18. The light emitting device package according to claim 15,wherein the metal member comprises a second heat sink.
 19. The lightemitting device package according to claim 15, further comprising: aphosphor layer around the light emitting device.
 20. The light emittingdevice package according to claim 15, wherein the electrode extends fromthe first portion to the outside.